#include <stdio.h>
#define WATER_MASS 3.0e-23
#define QUART_G 950.0

int main(int argc, char *argv[])
{
    int quart_num = 0;
    float water_molecule_num = 0;
    printf("Please inupt quart num:\n");
    scanf("%d", &quart_num);

    water_molecule_num = quart_num * QUART_G / WATER_MASS;

    printf("in %d quart water has %.2e water molecule.\n", quart_num, water_molecule_num);

    return 0;
}
